Tunnelling and Underground Space Technology最新文献

{"title":"Development of a predictive, risk-based model to assess the effects of maintenance decisions on vertical mine shaft structures","authors":"J.W. Wannenburg,&nbsp;G.N. Ngcobo,&nbsp;J Wannenburg,&nbsp;P.S. Heyns","doi":"10.1016/j.tust.2026.107481","DOIUrl":"10.1016/j.tust.2026.107481","url":null,"abstract":"<div><h3>Purpose</h3><div>The study addresses the challenge of effective long-term maintenance of the structures of vertical mine shafts. These structures face significant degradation over time due to corrosion, the impact of falling objects, and exposure to harsh environments with high humidity, chemical contamination, and poor ventilation. Current maintenance practices often prioritise short-term needs, neglecting the long-term consequences for structural integrity and operational sustainability. To bridge this gap, the research introduces a novel predictive risk-based maintenance decision-making model.</div></div><div><h3>Design/methodology/approach</h3><div>The model incorporates finite element analysis and Monte Carlo simulations to evaluate the failure modes caused by corrosion, fatigue and falling objects while accounting for uncertainties in degradation rates and impact probabilities. The analysis calculates the energy of falling objects and estimates corrosion rates based on environmental conditions, enabling accurate predictions of the remaining useful life (RUL) of critical steel components. This is combined with an Integrated Structural Inspection and Maintenance Management (iSIMM) system, which combines structural inspection data with Computerised Maintenance Management Systems (CMMS).</div></div><div><h3>Originality/value</h3><div>This model enables informed decision-making, enhancing safety, reliability, and cost-efficiency in mining operations. The research’s novelty lies in the integration of predictive and risk-based maintenance strategies, offering new insights into managing mine shaft structural integrity whilst integrating quantitative FEA-derived damage models (for impact) with stochastic, inspection-driven lifecycle simulation as a key methodological that enables the transition from qualitative inspection to predictive, risk-informed planning.</div></div><div><h3>Findings</h3><div>The model is used in a case study of a South African gold mine and demonstrates the practical application, showcasing its ability to optimise maintenance planning, reduce life cycle costs, and extend the lifespan of mine shafts, and to quantify the cost-risk trade-off between different multi-year maintenance strategies, a decision-support feature often missing in practice.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"171 ","pages":"Article 107481"},"PeriodicalIF":7.4,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Short-term surface settlements induced by EPBM twin tunnelling in saturated sandy soils","authors":"Binh Thanh Le ,&nbsp;Sam Divall ,&nbsp;Tra Nguyen ,&nbsp;Michael C.R. Davies","doi":"10.1016/j.tust.2026.107482","DOIUrl":"10.1016/j.tust.2026.107482","url":null,"abstract":"<div><div>This paper presents a case study of the construction of a 781-metre-long twin-tunnel, using an Earth Pressure Balance Machine (EPBM), in saturated sandy soils in Ho Chi Minh City, Vietnam. The depths of the tunnels were between 11.4m and 24.6m below the ground surface. The averaged trough width and length parameters were 0.326 and 0.446, which are consistent with previous studies in sands. The volume losses ranged from the anticipated levels of less than 0.5% to notably high values reaching up to 2.44%. Low volume losses were associated with areas of dense soil and effective tail void grouting. The characteristics of effective tail void grouting observed in dense sand in this project were grouting pressures close to porewater pressure, coupled with stable grouting volume that was approximately 130% of the volume of the theoretical tail void for the majority of the drive. However, in very loose sandy soil zones it was observed that even very high tail void grout volume did not prevent large settlements. Soil relative density proved to be an influential factor in ground surface vertical displacement, with large magnitudes occurring mainly in loose soil. A threshold relative density <span><math><mrow><msub><mi>I</mi><mi>d</mi></msub><mo>≈</mo><mn>0.4</mn></mrow></math></span> divides the normal volume loss of less than 0.7% range, and that of considerably larger volume loss. The results emphasised the need for caution when tunnelling at shallow depth in loose soil, where the combination of low relative density and shallow cover can result in significant ground movements.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"171 ","pages":"Article 107482"},"PeriodicalIF":7.4,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical investigation on the upstream–downstream thermal interactions during sequential artificial ground freezing (SAGF) of metro twin tunnels in high-seepage ground","authors":"Kangjian Zhang ,&nbsp;Zhiqiang Zhang ,&nbsp;Zhan Zhang","doi":"10.1016/j.tust.2026.107484","DOIUrl":"10.1016/j.tust.2026.107484","url":null,"abstract":"<div><div>Sequential artificial ground freezing (SAGF) provides improved frost heave control in urban tunnel engineering; however, its performance is challenged in high-seepage ground due to complex thermo-hydraulic interactions between the upstream and downstream freezing zones, where groundwater flow disrupts thermal symmetry and compromises curtain closure. This study focuses on the novel upstream–downstream interactions induced by sequential freezing under groundwater flow. A coupled thermo-hydraulic numerical model is developed to investigate the upstream–downstream effect during SAGF under various seepage velocities. The evolution of the temperature field, closure behavior, average temperature, and effective thickness of the frozen curtain is systematically analyzed. The results show that seepage velocities below 10 m/d cause asymmetric cooling that disrupts overall closure, whereas velocities exceeding 10 m/d lead to significant downstream cold energy transport, delayed closure, and potential non-closure of the frozen curtain. The closure time of the upstream freezing curtain increases exponentially when the seepage velocity exceeds a critical threshold of 7 m/d. In contrast, the closure time of downstream freezing exhibits a nonmonotonic response to seepage velocity, governed by the net cold energy balance. The frozen curtain develops pronounced asymmetry, with its consistently weakest zone located at approximately 225° relative to the tunnel center. These findings reveal the dominant mechanism of upstream–downstream thermal interaction under seepage conditions and provide quantitative design guidance for SAGF in high-seepage environments, highlighting the necessity of seepage-adaptive strategies in future engineering practice.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"171 ","pages":"Article 107484"},"PeriodicalIF":7.4,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cross-system modeling and analysis of cascading failure propagation in large-scale metro stations under extreme flooding events","authors":"Hai-Yun Li ,&nbsp;Dong-Mei Zhang ,&nbsp;Huan-Feng Duan ,&nbsp;Xu-Wei Zhao","doi":"10.1016/j.tust.2026.107483","DOIUrl":"10.1016/j.tust.2026.107483","url":null,"abstract":"<div><div>Climate-driven intensification of extreme precipitation is significantly increasing unprecedented flooding risks for underground transportation infrastructure. Current flood risk assessment approaches for large-scale metro stations, characterized by extensive subsystem integration, high passenger volumes, and complex spatial configurations, often fail to capture critical cross-system interactions. This limitation arises mainly from the artificial separation of simulations using computational fluid dynamics (CFD) from cross-system network analysis, which hinders the accurate prediction of cascading infrastructure failures. This study develops an integrated framework that combines CFD simulations with multi-layer network theory to concurrently analyze flood dynamics and system interdependencies. This framework models four critical subsystems of large-scale metro stations, including power, drainage, communication, and pedestrian, as interconnected networks based on established engineering standards. Flood-depth-dependent functions determine infrastructure node states, with thresholds calibrated from engineering standards to ensure physical consistency. The validations with the Shanghai Eastern Hub during a 500-year rainfall event (327 mm over 6 h, with a peak intensity of 90 mm/h) demonstrate that power systems exhibit the highest vulnerability, with functionality declining to 51.5% within 60 min. Furthermore, an analysis of 13,241 cascading failure events reveals that 67.3% are driven by water depth, while 32.7% are influenced by inter-system dependencies. Network analysis uncovers a critical importance-vulnerability paradox: power systems, serving as the network backbone with the highest importance score (0.446), simultaneously exhibit disproportionately elevated vulnerability (0.172) compared to other subsystems. The developed framework incorporates minute-level temporal coupling, validated to capture the dominant characteristics of infrastructure responses while maintaining computational tractability for engineering applications.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"171 ","pages":"Article 107483"},"PeriodicalIF":7.4,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Installation timing and deformation prediction of multi-layer supporting structures for deep-buried and soft-rock tunnels under high geo-stress","authors":"Zihan Zhou ,&nbsp;Bingyan Wang ,&nbsp;Wei Meng ,&nbsp;Keping Zhang ,&nbsp;Ziquan Chen ,&nbsp;Yuanfu Zhou ,&nbsp;Yuanming Lai","doi":"10.1016/j.tust.2026.107487","DOIUrl":"10.1016/j.tust.2026.107487","url":null,"abstract":"<div><div>Multi-layer supporting structures have excellent flexibility in dynamically regulating the stress release of surrounding rock. Therefore, accurately determining the installation timing and combination scheme is of great significance for preventing and controlling severe large squeezing deformation. To systematically sort out the principles for determining the installation timing, the evolution law of mechanical mechanism of the double-layer primary supports in Maoxian tunnel was analyzed. A theoretical analytical method for determining installation timing was proposed by combining the viscoelastic-plastic creep constitutive model, which considers the damage tensor of layered rock mass, with the elastoplastic model during the construction influence period and the failure model of the supporting structure. Based on the continuity requirement of deformation under a multi-layer supporting system, an artificial intelligence algorithm was used to establish a multi-level deformation prediction model, assisting in determining the installation timing. The results indicated that for continuous medium surrounding rock and large squeezing deformation, the concept of flexible support followed by strong support and appropriately delaying the installation timing, can significantly reduce the surrounding rock pressure. By adopting the above concept, the maximum surrounding rock pressure of Maoxian tunnel can be reduced from 950.7 kPa to 665.9 kPa. The applicability of the proposed theoretical analysis method and multi-level deformation prediction model was verified through engineering examples. The maximum analytical solution error of the average surrounding rock pressure in Maoxian tunnel was only 41.2 kPa, while the average deformation prediction error was only 8.3%.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"171 ","pages":"Article 107487"},"PeriodicalIF":7.4,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Model tests and discrete element simulations on the cracking characteristics of layered soft rock tunnel under different bedding features","authors":"Wenbo Yang ,&nbsp;Haoyu Li ,&nbsp;Changhui Zhao ,&nbsp;Fangyin Wu ,&nbsp;Liangliang Zhao","doi":"10.1016/j.tust.2026.107454","DOIUrl":"10.1016/j.tust.2026.107454","url":null,"abstract":"<div><div>The angle and direction of bedding have a significant influence on the cracking and damage observed in tunnels excavated through layered soft rock. To investigate the cracking characteristics of tunnel lining structures under varying bedding conditions, this study initially conducted layered soft rock tunnel cracking tests. By analyzing the acoustic emission signals, lining deformation, and evolution of mechanical behavior during the loading process, the spatial distribution of lining cracking locations was determined for different bedding characteristics. Based on this, the cracking characteristics and crack patterns of the lining and surrounding rock were revealed using discrete element simulation. The study results indicated that bedding planes in their normal orientation represented a high-risk area for lining cracking due to stress concentration and inward compression of the lining, which resulted in the rupture of contact force chains and the initiation of cracks. Besides, the bedding characteristics exerted a significant impact on the crack pattern of the tunnel lining. Among these, the crack pattern of the lining evolved from tension/compression to shear, and then back to tension/compression, with deformation and internal forces showing an increasing and then decreasing trend, reaching a peak at an angle of 45°. As the bedding direction increased, cracks transitioned from a dispersed distribution to longitudinal penetration, while shear failure became more pronounced. The deformation and internal forces continued to increase, and the tunnel’s bearing capacity was weakest at a direction of 90°. This study systematically uncovers the failure mechanisms of layered soft rock tunnels, offering direct support for optimizing tunnel support parameters and a theoretical basis for maintaining existing tunnels.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"171 ","pages":"Article 107454"},"PeriodicalIF":7.4,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146048428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A new rock cutting and splitting method for hard-rock excavation: methodology, scaled model test and numerical modelling, and field validation","authors":"Jung-Woo Cho ,&nbsp;Hoyoung Jeong ,&nbsp;Sang-Hwa Yu ,&nbsp;Hee-Suk Lee","doi":"10.1016/j.tust.2026.107477","DOIUrl":"10.1016/j.tust.2026.107477","url":null,"abstract":"<div><div>Rock cutting and splitting is a new mechanical excavation method that consists of two steps: cutting with a saw and splitting with a wedge. The rock is cut to a prescribed depth in the first step, then each block is split by inserting a wedge into the cut. The main failure mechanism is tensile crack propagation from the base of the block towards the free face. We introduce an analytic solution to estimate the required indenting force. A series of scaled model tests confirmed that effective block separation occurs when the spacing-to-depth ratio is &lt;2.0. Numerical models reproduce the tensile fracturing mechanism and validate the experimental results. Finally, in situ excavation tests on a granite slope and a simulated tunnel face demonstrate the applicability of the method to real-world situations. In hard rock (UCS &gt; 100 MPa), the net cutting rate of CS method was 20 %–30 % higher than that predicted for roadheaders and more than 600 % higher than that of impact hammers. Photogrammetric surveys confirmed that the block shape matches the intended shape, suggesting the potential reuse of the blocks as construction material.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"171 ","pages":"Article 107477"},"PeriodicalIF":7.4,"publicationDate":"2026-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Muck particle transport behavior and Cutterhead-Agitator synergistic optimization for EPB shield tunneling in sandy pebble strata","authors":"Yuxiang Yao,&nbsp;Jian Cui,&nbsp;Zhigang Yao,&nbsp;Xiongyu Hu,&nbsp;Yong Fang,&nbsp;Chuan He","doi":"10.1016/j.tust.2026.107473","DOIUrl":"10.1016/j.tust.2026.107473","url":null,"abstract":"<div><div>Sandy pebble strata, characterized by high pebble content, high uniaxial compressive strength (UCS) of pebbles, poorly-sorted grain size distribution, and low flowability, often induce muck accumulation, cutterhead clogging, and chamber caking during earth pressure balance (EPB) shield tunneling, thereby reducing construction efficiency and compromising safety. Existing studies, predominantly relying on macroscopic indicators, often fail to elucidate the mesoscopic particle transport behaviors and the synergistic mechanism of the cutterhead-agitator system. This study develops a full-scale, three-dimensional finite difference method-discrete element method (FDM–DEM) coupled model to simulate particle transport within the cutterhead and soil chamber, to systematically reveal the transport mechanisms and guide equipment optimization. Results indicate that: (1) the soil chamber exhibits a “core–ring” dual-flow structure, characterized by a low-velocity “dead-zone column” at the center and a high-velocity annular channel at the periphery, attributed to the limited opening ratio in the central area and insufficient agitator coverage; (2) a “barrier–channel–dead-zone column” triple-control mechanism is proposed to explain the constraints imposed by energy barriers, geometric confinement, and cascade migration on particle transport; and (3) a synergistic optimization strategy is proposed, which includes increasing the opening ratio in the cutterhead’s central region, installing vertical agitators at the chamber center, and relocating the inner-ring agitator to R = 1.8 m. These findings provide significant theoretical insights for understanding muck transport behaviors and optimizing EPB shield design in sandy pebble strata.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"171 ","pages":"Article 107473"},"PeriodicalIF":7.4,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multiple-branching hierarchical fusion network for tunnel blasting excavation shape prediction using measurement while drilling data","authors":"Jun Wang ,&nbsp;Qian Fang ,&nbsp;Jinkun Huang ,&nbsp;Guoli Zheng","doi":"10.1016/j.tust.2026.107479","DOIUrl":"10.1016/j.tust.2026.107479","url":null,"abstract":"<div><div>Tunnel excavation shape characteristics using the drill-and-blast method are influenced by blasting parameters and geological conditions. Meanwhile, these excavation shape characteristics significantly impact tunnel stability, support construction quality, and construction costs. Traditional approaches for predicting excavation shape characteristics exhibit limitations in terms of accuracy and efficiency. To address this, we propose a multiple-branching hierarchical fusion extraction network (MBHF) for predicting tunnel excavation shape characteristics, including overbreak/underbreak values, cross-sectional curvature, and regional convexity/concavity. The MBHF model employs a multi-branch module for multi-attribute feature extraction and a gated structure for multi-source data fusion. It integrates construction parameters, blasting parameters, and measurement-while-drilling (MWD) data as inputs. The proposed MBHF model’s performance and superiority in feature extraction and fusion have been validated through ablation studies and comparative analyses. On the testing dataset, the model achieved high predictive accuracy, with R2 values of 0.97, 0.89, and 0.88 across the three prediction tasks. The multi-task learning strategy demonstrates superior performance compared to the single-task learning strategy in predicting excavation shape characteristics. The weight-constrained graph convolutional networks exhibit exceptional performance than the traditional graph convolutional networks in extracting features from MWD data. Increasing MWD data points (blasthole number and length) significantly enhances model performance, but performance declines beyond a certain threshold.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"171 ","pages":"Article 107479"},"PeriodicalIF":7.4,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermomechanical behavior and damage mechanism of the lining backfill body of high-temperature thermal energy storage reservoirs in mines","authors":"Gang Xu ,&nbsp;Pengfei Shan ,&nbsp;Xingping Lai ,&nbsp;Qinxin Hu ,&nbsp;Shangtong Yang ,&nbsp;Huicong Xu","doi":"10.1016/j.tust.2025.107409","DOIUrl":"10.1016/j.tust.2025.107409","url":null,"abstract":"<div><div>The construction of underground thermal energy storage (UTES) systems using the space of abandoned mines is one of the most promising large-scale energy storage methods for the future. However, thermal fatigue damage caused by high-temperature environments may trigger potential destabilization of the backfill body that surround the thermal energy storage reservoir. It is therefore worthwhile to investigate the mechanism of mechanical weakening of the backfill body due to temperature effects. In this study, backfill body samples were subjected to heat treatment at six temperature levels and static mechanical testing. The thermomechanical behavior of the backfill body at different heating temperatures was investigated. Through acoustic emission (AE) technology and scanning electron microscope (SEM), the damage evolution law and instability precursors of the backfill body under thermomechanical effects were analyzed, revealing the crack propagation behavior and damage weakening mechanism of the backfill body. The results show that when the heating temperature rose from 25 °C to 500 °C, the compressive strength and elastic modulus of the backfill body decreased by 78.61 % and 84.21 %, and the peak strain increased by 62.54 %. High temperatures significantly weaken the mechanical properties of backfill body samples, promote plastic softening in the samples, and increase their ductility and deformation capacity. This is microscopically attributed to the structural damage to the backfill body caused by the progressive decomposition of ettringite, calcium silicate hydrate, and calcium hydroxide in high-temperature environments. This effect is visible in the SEM images of the microstructure of the backfill body and is dominated by the temperature level. The evolution patterns of AE counts and <em>b</em>-values effectively characterize the damage process of the backfill body and provide valuable early warning information for its fracture instability. As the temperature increased, the proportion of shear cracks rose from 31.72 % to 74.18 %. High temperatures significantly accelerate the formation and propagation of shear cracks, ultimately leading to a tensile-shear hybrid failure in the backfill body dominated by shear cracking. The research results provide theoretical references for the reinforcement design and disaster warning of defect-sensitive areas in thermal energy storage reservoir in UTES projects.</div></div>","PeriodicalId":49414,"journal":{"name":"Tunnelling and Underground Space Technology","volume":"171 ","pages":"Article 107409"},"PeriodicalIF":7.4,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}